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Green smoothies are all the rage these days. Many people are drinking them every day or at least several times a week in an attempt to get healthy and “alkalize” the body.
Whenever I visit the cafe of my local healthfood store, there are usually several people in gym clothes lined up to order a green smoothie to sip after their workout.
Green smoothies are made by blending large amounts of raw leafy green vegetables with fruit to soften and sweeten the taste. Typical vegetables included in green smoothies are cruciferous vegetables like kale, broccoli, collard greens, maca (usually as a supplemental powder) as well as others like spinach, swiss chard, celery, and parsley.
Is the green smoothie fad a truly healthy habit over the long term? Or, could regular consumption of these seemingly healthy drinks contribute to serious health problems over time?
Raw Leafy Greens Contain High Oxalate Levels
Frequent consumption of large quantities of raw, leafy green vegetables blended up as green smoothies can be deceiving at first. This is because green drinks facilitate an initial detoxification process that makes a person feel great. This is especially true when coming off a highly processed, nutrient poor diet.
While very nutritious, the vegetables used in green smoothies are almost without exception high oxalate foods. Over time, a high oxalate diet can contribute to some very serious health problems particularly if you are one of the 20% of people (1 in 5) that have a genetic tendency to produce oxalates or if you suffer from candida or other fungal challenge. In those cases, a high oxalate diet can deal a devastating blow to health.
Oxalate Toxicity Not a New Problem
The effects of oxalate toxicity have plagued humankind since ancient times. For example, scientists discovered an oxalate kidney stone about the size of a golf ball in a 2000 year old mummy from Chile using x-ray analysis.
Build-up of shards of oxalate crystals can occur almost anywhere in the body. Whatever tissue contains them, pain or worse is the result.
75-90% of kidney stones are oxalate related with 10-15% of Americans afflicted at some point during their lives. As the star shaped crystalline stones pass from the kidney, they cause pressure and pain in the bladder and urethra and can actually tear up the walls of the urinary tract.
Oxalate Stones from Excessive Green Smoothies
Oxalate stones can show up in any body tissue including the brain and even the heart.
Crystals comprised of oxalates resemble shards of glass. They can become lodged in the heart causing tiny tears and damage to this vital muscle. With every single contraction, more damage is caused as the heart pumps life giving blood to the rest of the body.
Oxalate crystals which end up in the thyroid can cause thyroid disease by damaging thyroid tissue.
A frequent location for oxalates to end up is skeletal muscle which will cause pain with even normal movement and make exercise nearly impossible. Dr. William Shaw, Director of The Great Plains Laboratory for Health, Nutrition and Metabolism who has studied oxalates extensively, is convinced that oxalate toxicity is a factor in fibromyalgia the pain of which can absolutely devastate a person’s life (1).
Vulvodynia – Painful Sex
Cases of women experiencing painful sex are on the rise with oxalates a possible culprit.
Vulvodynia is a condition causing pain in and around the vagina. It is linked to oxalates deposited in this delicate reproductive tissue. Oxalate crystals are very acidic and they cause irritation, burning, and stinging sensations for affected women. An accompanying feeling of rawness is typically experienced during sexual relations.
Oxalates Are Fungal in Origin
A surprising finding is that oxalates are produced in large amounts by fungus. Large stones have been found in the sinuses and lungs of people suffering from systemic fungal infections such as candida or Aspergillus.
Therefore, anyone who suffers from any sort of candida overgrowth or other fungal challenge like fungus nails or dandruff would be wise to be very concerned about oxalate intake via the diet.
Consumption of green smoothies would not in any way contribute to improvement of health in these situations. The majority of people today suffer from gut imbalance and candida (yeast) issues caused by antibiotic and prescription drug use including the Pill. This renders a high oxalate diet which includes frequent green smoothies an unwise practice for virtually everyone.
Does Cooking Destroy Oxalates?
What about cooking the greens first? Would this reduce the risk of oxalate overload and make consuming greens safer?
Not really, because oxalates are extremely stable. While cooking high oxalate foods and discarding the cooking water does reduce the level of anti-nutrients, it remains quite high.
Green smoothies are usually consumed frequently by those who swear by them. As such, a light steaming of the veggies first would not make a significant difference over the long term if they are consumed regularly. If you consume green smoothies only occasionally, however, a light steaming is a good idea. This practice adds a degree of safety to the process. Other tips for preparing safe smoothies are contained in this linked article.
Healthier Alternatives to Green Smoothies
The best course of action for health, then, is to opt out of the green smoothie diet fad. This is especially important if you have any sort of gut imbalance or candida issues.
If you enjoy green leafy vegetables, be smart about it. Don’t overdo like so many in the health community are doing with the best of intentions. Enjoy green drinks in moderation in salads. Or, cook them and carefully drain and discard leafy green cooking water. Never use it in soups and sauces!
Be sure to serve cooked leafy greens with a healthy fats like butter or coconut oil. Avoid margarine or any factory fats synthesized with rancid and/or GMO vegetable oils like Smart Balance. Using natural fats will facilitate maximum absorption of minerals.
Another option is to drink raw cultured vegetable juice or eat raw cultured vegetables. Not only will you get enhanced nutrition from the culturing process which adds enzymes and nutrients, but you will also get a beneficial and therapeutic dose of probiotics to help balance gut function and improve digestion. It also suppresses fungal overgrowth like candida.
Wheatgrass an Excellent Alternative!
Another option is to do shots of fresh, green wheatgrass juice.
Wheatgrass juice is very low in oxalic acid.
Here is a link to my favorite green juice recipe using wheatgrass and ginger. It is safe to drink regularly, daily if you like, instead of green smoothies. It is also an excellent drink for gently detoxing before pregnancy. The ginger assists with morning sickness issues too if you are already pregnant.
What to do if a Green Smoothie Diet Has Already Harmed Your Health
Are you already are suffering from some of the ailments described in this article? Do you suspect a high oxalate diet which includes green smoothies or a daily spinach salad may be the cause? If so, stop this practice immediately and consult with a holistic physician. You will likely need professional assistance to guide you on the road to recovery. Ridding your body of oxalate crystals that are potentially irritating one or more of your body tissues is no simple task! It is not advisable to attempt this protocol on your own.
Sarah, The Healthy Home Economist, author, Get Your FATS Straight
References and Additional Information
The Role of Oxalates in Autism and Chronic Disorders, William Shaw PhD
Top 4 Cleansing Myths to Watch Out For
Oh please, Sarah. We all know it’s just a clickbait title to gain attention and the message pointless. Is a burger better then? Yes? Or grains? What would you suggest? Oh wait. I don’t want to know because I feel great with my green smoothies and I look the best I’ve ever looked.
Glad the green smoothies are working for you! Be sure not to overdo, which unfortunately most people do in my experience. And yes, you can feel and look great for quite awhile doing them until all of a sudden you have serious problems. Here are some tips for consuming them sensibly and safely since you obviously are enjoying them: https://www.thehealthyhomeeconomist.com/green-smoothie-safety-tips/
Well all food is bad for you these days. Bread and grains are bad. Meat and dairy is bad. Fruit is full of sugar. now vegetables is bad for you. I am becoming a nofoodatarian.
The main sources of oxalate in diets were regular tea and coffee (80-85%). Only 15-20% of oxalate was derived from other plant foods.
I think we should focus on our caffeine consumption before worrying about green smoothies.
You are not considering the fact that green smoothies involve an enormous pile of greens blended into a single drink … far more greens than a person would consume in a salad. It is the sheer volume of oxalate containing greens in a single green smoothie combined with the addictive behavior of some of its fans who consume them day after day after day that is the problem.
Lol, this is exactly how I feel. Everything is bad. I’m tired of all those food rules. Just try to eat mostly whole foods. Period. Don’t sweat the rest.
Did this article say green veggies are bad? No, it did not. It said that green smoothies are a fad … just trying to clue you in before you get damaged by it. Just eat veggies like traditional cultures did!
Hello Sarah,
The warning seems to concern those individuals whom frequently (assuming to mean multiple times a day, every day) consume large amounts (perhaps 32 oz) of green smoothies. May I read between the lines and gather that one who consumes once a day in the morning a smoothie consisting of spinach, strawberries and banana, and water, which makes a serving of approx 25-30 oz, and goes on eating sensibly the rest of the day would be fine? Sensibly like, salad and lean meat, things of this nature.
Thank you,
Oscar
Fine to say ancient traditional cultures were healthy because they ate vegetables in the good old conventional way Sarah, but you don’t take into account the fact that blenders hadn’t been invented yet … and you can’t be sure that their veggie eating habits were better ‘cos they’re all dead anyway … hehe
Sorry, I’m not buying it. And why are we calling green smoothies a fad. I think we’re past that point by now. Now that they’ve been around for over 5 years…hardly a fad. Besides, if it were a fad, where do we go from here? Is there something better than plant-based in the history of the world? Is there something else out there that will be all the rage that kicks green eating to the curb? Unfortunately, eating plant-based is relatively knew, but with how it’s caught fire, it’ll never go away again…not with such high rates of cancer and not with the level that organic has grown to in recent years.
Hi Sarah,
Can you address greens powders? Are they as dangerous as a green smoothie? I take a very high quality powder by Douglas Labratories but now that I’ve read your article, I’m questioning whether it’s a good idea. Can you weigh in?
This is a great question. I have not delved into this, so can’t give a firm answer as of yet. Let me do some digging!
Use Romaine Salad instead, it is very low in Oxalate. I use it mostly.
I also use romaine in my smoothie along with coconut water/hemp seed/chia seeds/avocado/frozen banana. I often have this for dinner. I have low thyroid so know to avoid oxalates altho I also juice daily and sometimes put a leaf of kale along with carrot/parsley/apple/celery/cucumber/etc.
I really would like to see some REAL citations in these kinds of article. Like from PubMed. There is waaaayyyy too much information out there and I am not buying all this stuff anymore without some real research backing up this stuff. I have been eating green smoothies every morning for that past 5 years with zero ill effects. Show me a few well-designed studies and I’ll switch.
Formal studies take many years to fund, conduct and publish … by then it is far too late for those who bought into a health fad and lost their health in the process. It is wise to listen to experts in the field such as Dr. Shaw cited in the article who can provide guidance before it is too late. Common sense doesn’t need pubmed.
Please, can you contact me directly? I am dying from that green smoothie.. well I feel like I am.. now I have chest pains. I fall down the stairs… its been one thing after another since I drank 1 green smoothie. I need to know who you said to contact.. I cant find the reply now.. Thank you
Apparently you don’t know about non oxalic green, like lettuce and baby spinach. Just use them for your green smoothies and you will not have the kind of problems that you describe in your article.
Can oxalates cause gall stones? I have lots of indications that I have developed secondary hyperoxluria through being given vast amounts of antibiotics for Lyme and unwittingly eating a high oxalate diet (smoothies). A few years ago I had a couple of gallstones. Now it’s packed full. There are slight calcifications in the kidneys but no stones. For that reason I can’t get recognition or treatment. No doctor I’ve met so far has heard of illness and the nephrologist can only help if the kidneys are involved. Any research papers or instances where there is gallstone involvement? My body burns and crawls in horrific pain.
Whoa!! Please don’t throw the baby out with the bath water!
I appreciate your article for the very small percentage of people who may have an issue with kidney stones or other issues caused by high oxalate consumption.
However, I’m afraid for many reading this article it may lead them to unnecessarily reduce their consumption of these greens. Being in private practice for over 30 years, using a high vegetable, moderate protein, grain free, blood sugar stabilizing diet on approximately 95% of my patients, I believe I have seen one patient following this kind of regime that “might” have passed a kidney stone. Mind you, I have patients who have been with me for the entire 29 years I have been practicing in Santa Barbara. I have seen a fair number who in their health history had previously had kidney stones, but not while following this kind of regimen.
I know how painful these stones can be to pass, as I kept a young pregnant patient in my clinic all day many years ago, putting her through a specific protocol to help her pass her stones. She had been sent home from the hospital as they couldn’t blast her stone when pregnant and she didn’t have insurance. She was vomiting, in pain, severely nauseous and dangerously dehydrated. Luckily we were successful and she had a full quick recovery.
I am not a proponent of “smoothies” on a regular basis, so my patient base is not drinking that level of the greens you mention, but it is common for them to have many of these greens in their diet and a much higher level of greens than the average American. Especially given the plethora of beautiful, organic greens that we have locally.
The health benefits of these greens have been well documented, in spite of the gentleman who is promoting his anti-greens book, the conclusions of which, myself and many docs would find faulty.
I would say the benefits of eating large amounts of these greens, very much outweigh the risks, with the exception of someone who has a history of kidney stones. Even then there are many other variables that can contribute to the cause of stones.
Regarding patients who have yeast problems and these greens, having treated patients with yeast problems my entire career, I have never limited their greens and they always get their yeast issue resolved and believe me I have seen yeast problems so severe they had landed patients in the hospital, near death before they saw me.
Again, I conclude say that for the vast percentage of people, eating a diet high in greens has way more benefits than risks.
Options for consuming greens safely is included in the article.
Unless you’re drinking ridiculously large amounts of green smoothies, consuming green vegetables has more benefits than risks. I think green smoothies are a great add on to anyone’s diet. And if your argument is on the oxalates found in green plant foods, why not look at the oxalates found in coffee and black tea, and the large quantities of coffee some people consume everyday. If anything I’d be more worried about how much coffee and black tea people are drinking, not green smoothies.